Projectile

ABSTRACT

An ammunition projectile which can be selectively fired in weapons having either a smooth bore or spin imparting gun barrel. The projectile has on the main body an annular bore rider which is longitudinally spaced forwardly of the rotating band. The peripheral surface of the main body, intermediate the bore rider and rotating band, has an annular pressure centering or positioning recess.

United States Patent [1 1 Travor et al.

[ 1 Oct. 21, 1975 PROJECTILE Inventors: Bruce W. Travor, Holland, Pa;

Samuel L. Brown, Willingboro, N.J.; Brian D. Wenocur, Audubon, Pa.

The United States of America as represented by the Secretary of the Army, Washington, DC.

Filed: Dec. 19, 1973 Appl. No.: 426,270

Assignee:

US. Cl. 102/93; 102/52 Int. Cl. F42B 13/16; F42B 13/04 Field of Search 102/93, 52

References Cited UNITED STATES PATENTS 12/1937 Foulke ..l02/92.1 3/1938 Gerlich ..102/92.1

2,324,346 7/1943 Albree 244/3.1 2,998,778 9/1961 Hablutzel 102/93 3,446,147 5/1969 Engel et al 102/93 3,447,466 6/1969 Engel 102/93 Primary Examiner-Harvey E. Behrend Assistant Examiner-C. T. Jordan Attorney, Agent, or FirmNathan Edelberg; Robert P. Gibson [57] ABSTRACT An ammunition projectile which can be selectively fired in weapons having either a smooth bore or spin 3 Claims, 1 Drawing Figure US. Patent 0a. 21, 1975 Ill Llll ll lllll lr li .lllluln III. I III PROJECTILE The invention described herein may be manufactured, used, an licensed by or for the Government for governmental purposes without the payment to us of any royalty thereon.

This invention relates to projectiles, and more particularly to an ammunition projectile having a main body and an aerodynamic windshield or nose.

Since the advent of flechette type ammunition, the interchangeability of conventional type ammunition with smooth bore ammunition has been desirous.

One of the objects of the invention is to provide an ammunition projectile which can be fired from conventionally rifled barrels as well as from smooth bore barrels.

Another object of the invention is to provide such a projectile which will not adversely sacrifice the operational perfonnance of the ammunition round.

A further object of the invention is to provide such a projectile that can be fired in conventional rifled orsmoothbore weapons which do not require costly modifications.

These and other objects, features and advantages will become more apparent from the following description and accompanying drawing which is an elevational view, partially broken away in section, of a preferred ammunition projectile embodying the principles of the invention.

The ammunition projectile, shown generally at has a main body 11 of conventional materials well known in the art and having a forwardly opening cavity 12 that force-fittingly receives the rearwardly extending cylindrical portion 14 of a windshield or nose penetrator member 13. The rearward end of the main body has a crimping groove 15 for attachment of a cartridge case, and slightly forward thereof, a rotating band 16 of a copper base material for conventional engraving by and sealing of the rifling grooves of a spin imparting gun barrel. Spaced longitudinally from and forward of the rotating band is a bore rider annulus 17, of similar material as and less diameter than rotating band 16, that is only partially engraved by the rifling grooves while functioning as a forward guide. The bore rider annulus 17 is preferably located rearwardly adjacent the conically tapered forward surface portion 18 of the main body, said conical surface being a continuation of the nose conical surface.

For the purpose of selectively employing the projectile in similar sized smoothbore gun barrels wherein both the band 16 and bore rider 17 function as longitudinally spaced guides, an annular recess 20 is provided in the peripheral surface of main body 11 between the bore rider annulus and rotating band. Preferably, the depth of the recess is such that the ratio of diameters of the recessed peripheral surface and the main body is .765, although the permissible ratio range from .725 to .805 will provide an operationally appropriate center of pressure or pressure positioning rearwardly of the projectile center of gravity. The leading and trailing edges 21, 22 of the annular recess 20 preferably should be at least 30, as shown to assure proper positioning of the operational center of pressure into the recess 20 for aerodynamic stability of the smoothbore fired projectile, although these conical fillet edges 21, 22 may be of a suitable arcuate contour. Also, the ratio of the total width (including edges 21, 22) of the recess 20 compared to the depth of the recess should be approximately 6.3:1 for a 22 conical nose, although a satisfactory ratio range of 5.9:1 to 6.7:1 will provide an appropriate center of pressure.

Various modifications, alterations or changes may be resorted to without departing from the scope of the invention as defined in the appended claims.

We claim:

1. A projectile for selective use in smoothbore and spin imparting gun barrels, comprising a main body having a forwardly opening cavity at one end thereof and means at the rearward end of said body for securing a cartridge case,

a nose penetrator member having a cylindrical portion secured in said cavity and a forwardmost conical surface portion,

a rotating band secured on said main body forwardly of said cartridge securing means,

an annular bore rider on said main body and longitudinally spaced forwardly of said rotating band, said main body having a conically tapered surface portion forwardly adjacent said bore rider and defining a continuation of said nose conical surface, and

means on said main body of said projectile for positioning an operational aerodynamic center of pressure rearwardly of a center of gravity for said projectile, said positioning means including an annular recess in the peripheral surface of said main body intermediate-said bore rider and rotating band.

2. The structure according to claim 1 wherein the ratio of diameters of said recessed peripheral surface and said main body is in the range of .725 to .805.

3. The structure of claim 2 wherein said ratio is .765. 

1. A projectile for selective use in smoothbore and spin imparting gun barrels, comprising a main body having a forwardly opening cavity at one end thereof and means at the rearward end of said body for securing a cartridge case, a nose penetrator member having a cylindrical portion secured in said cavity and a forwardmost conical surface portion, a rotating band secured on said main body forwardly of said cartridge securing means, an annular bore rider on said main body and longitudinally spaced forwardly of said rotating band, said main body having a conically tapered surface portion forwardly adjacent said bore rider and defining a continuation of said nose conical surface, and means on said main body of said projectile for positioning an operational aerodynamic center of pressure rearwardly of a center of gravity for said projectile, said positioning means including an annular recess in the peripheral surface of said main body intermediate said bore rider and rotating band.
 2. The structure according to claim 1 wherein the ratio of diameters of said recessed peripheral surface and said main body is in the range of .725 to .805.
 3. The structure of claim 2 wherein said ratio is .765. 